The present invention relates to a pump assembly, and in particular to a bearing arrangement in a pump assembly.
Pump assemblies usually comprise a drive device, for example an electric motor, a rotor shaft and an impeller arranged thereon. The rotor shaft thereby, must be mounted in the axial and radial direction. In particular, the pressure forces acting on the impeller on operation of the pump must be accommodated in the axial direction. For this, with regard to pumps with canned motors or magnet couplings with cans in the drive unit, usually a bearing is arranged at the axial end of the rotor shaft in the can. The problem with this mounting is the bearing may often not be adequately cooled or lubricated.
Furthermore, with multi-stage pumps, it is a problem that the tolerances in each pump stage sum, so that on assembly, it is necessary to position the pump impellers relative to the rotor shaft, or to provide an axial compensation in the coupling between the drive motor and the rotor shaft.